The modern “mini-gun,” or M-134, can trace its origins to the original Gatling gun of the mid-nineteenth century. It is a machine gun which fires projectiles in an automatic fashion. In the process of firing these projectiles, the gun utilizes a plurality of barrels (usually six) which consecutively rotate in a circular circuit into a single position which allows for the firing of a projectile. Each barrel, then, is only used to fire one-sixth of the projectiles, spending the remaining time cooling in an air current caused by the rotation of the barrels. Over time, many improvements have been made to the original Gatling gun, resulting in the modern M-134. However, each variant of the M-134 has always featured the rotatable barrels which are the signature characteristic of this family of firearms.
Most modern firearms utilize cartridge ammunition. As cartridge is a fairly simple structure, with a projectile, or bullet, nested over an explosive charge of propellant. The charge and projectile are held together by a casing, or head. This casing presents a rearward primer which, when crushed, ignites and this ignition travels to the charge, igniting it explosively and thereby providing the impetus for launching the projectile. In most modern firearms, particularly with rifles, the primer is impacted by a firing pin. This firing pin is a spring-loaded hammer residing within a firearm bolt and, when released, impacts the primer of properly seated ammunition. The firearm bolt is also used to seat the next successive round of ammunition and, frequently, aids in the ejection of spent cartridges. Usually in an M-134 or Gatling variant, each barrel will have its own bolt. The bolt usually has a body and a head which is movable (rotatable) with respect to the body.
The bolts and barrels are mounted upon a rotor. The rotor is driven by a drive gear connected to the motor of the firearm and, often, serves as a connection to translate rotational motion to a delinker gear so that the firearm delinker may be run from the same motor. It is important that the drive gear and the delinker gear maintain correct timing with respect to each other for proper firearm function. The rotor also provides the structure which keeps each barrel and bolt pair in-line while rotating and allows the longitudinal displacement of each bolt as it travels with the rotor. This structure also features a lock structure for each bolt which secures the bolt at its forward-most (firing) position as each bolt head twists to release its contained firing pin (a process explained in co-pending application Ser. No. 15/000,272, which is incorporated herein by reference in its entirety). Over time, the lock structure wears to the point it requires replacement for the proper functioning of the firearm. Likewise, the gears also wear. When these events occur, the parts must be replaced and, possibly, the entire rotor may have to be replaced.
The present invention represents a departure from the prior art in that the rotor of the present invention allows a replaceable and reversible lock structure, for extended useful life of the lock parts. It also features replaceable gears keyed into the structure of the rotor. This mitigates the need to replace the rotor when gears are worn. Both of these features extend the useful life of the rotor itself and reduce the cost of maintenance of the firearm. A rotor of the present invention may be further adapted to be backwards compatible with existing rotating firearms and be readily usable in future designs.